In recent years, as a result of automation, many electronic devices are used extensively in various locations in plants, laboratories, offices, hospitals, sporting facilities such as golf courses, and agricultural facilities, etc. These electronic devices are usually vulnerable to surge voltages from lightning.
The surge voltages can enter electronic devices via telephone and other communication lines, as well as via a power source. Therefore, lightning arresters are often needed at both points of entry. Some of the above-mentioned facilities may be located in regions where thunderstorms frequently prevail. Furthermore, when the facilities are located at mountainous regions, dry riverbeds or sand dunes, the resistivity of the facility sites is relatively high. Consequently lightning currents at high resistivity sites will not immediately dissipate in the ground but can travel through adjacent electric power lines to other areas where such currents can cause great damage.
In addition, unmanned, electronically controlled facilities increase in number with the spread of automation. These unmanned facilities require that personnel be dispatched from distant locations when problems occur in the lightning arresters.
Since the demand for lightning arresters is steadily increasing, there is a need for an improved lightning arrester to simplify maintenance requirements and reduce maintenance costs. The improved lightning arrester should be capable of withstanding greater energy surges than known lightning arresters, protect electronic devices from repeated strikes of heavy lightning surges, and also avoid burnout within the lightning arrester itself.
A lightning arrester for high sensitivity of low voltage circuits, in accordance with the present invention, is thus proposed for the above-mentioned purposes, and for extensive application in various fields.